Sift together flour, 2 tablespoons sugar, baking powder, soda, and salt in a medium mixing bowl. Stir in 1 tablespoon lemon rind. Cut in shortening using a pastry blender until mixture resembles coarse meal. Add buttermilk and lemon extract, stirring until dry ingredients are moistened.
Turn dough out onto a lightly floured surface; knead lightly 10 to 12 times.
Roll dough to 1/4-inch thickness; cut with a 1 3/4-inch biscuit cutter.
Combine remaining sugar, lemon rind, and juice in a small bowl. Sprinkle 1/4 teaspoon mixture over half of biscuits. Top with remaining biscuits, pressing together lightly.
Place biscuits on greased baking sheets. Bake at 450° for 8 minutes or until golden brown. Remove from baking sheet, and serve immediately.